Search results
Results from the WOW.Com Content Network
Polarizability is responsible for a material's dielectric constant and, at high (optical) frequencies, its refractive index. The polarizability of an atom or molecule is defined as the ratio of its induced dipole moment to the local electric field; in a crystalline solid, one considers the dipole moment per unit cell. [1]
The polarizability of individual particles in the medium can be related to the average susceptibility and polarization density by the Clausius–Mossotti relation. In general, the susceptibility is a function of the frequency ω of the applied field.
Different states of polarization correspond to different relationships between polarization and the direction of propagation. In linear polarization , the fields oscillate in a single direction. In circular or elliptical polarization , the fields rotate at a constant rate in a plane as the wave travels, either in the right-hand or in the left ...
That is, the polarization is a convolution of the electric field at previous times with time-dependent susceptibility given by (). The upper limit of this integral can be extended to infinity as well if one defines χ e ( Δ t ) = 0 {\displaystyle \chi _{\text{e}}(\Delta t)=0} for Δ t < 0 {\displaystyle \Delta t<0} .
Polarizability, an electrical property of atoms or molecules and a separate magnetic property of subatomic particles Polarization function, a feature of some molecular modelling methods; Photon polarization, the mathematical link between wave polarization and spin polarization
However, care is needed because some authors [6] take out the factor from (), so that = and hence () = /, which is convenient because then the (hyper-)polarizability may be accurately called the (nonlinear-)susceptibility per molecule, but at the same time inconvenient because of the inconsistency with the usual linear polarisability definition ...
The static permittivity is a good approximation for alternating fields of low frequencies, and as the frequency increases a measurable phase difference δ emerges between D and E. The frequency at which the phase shift becomes noticeable depends on temperature and the details of the medium.
Molar refractivity, [1] [2], is a measure of the total polarizability of a mole of a substance. For a perfect dielectric which is made of one type of molecule, the molar refractivity is proportional to the polarizability of a single molecule of the substance. For real materials, intermolecular interactions (the effect of the induced dipole ...